package com.example.designpatterns.model.observer;

import org.apache.logging.log4j.message.Message;

/**
 * @author yanyun zhu
 * @version 1.0
 * @date 2022/1/4 9:07
 */
public interface Subject {
    void registerObserver(Observer observer);
    void removeObserver(Observer observer);
    void notifyObservers(Message message);
}
